Film forming method

Abstract

The present invention is a film forming method, which is a film forming method for performing a heat treatment on mist in a film forming section to form a film, comprising: a step of atomizing a raw material solution in an atomizing section to generate mist; a step of transporting the mist from the atomizing section to the film forming section via a transport section connecting the atomizing section and the film forming section by a carrier gas; and a step of performing a heat treatment on the mist in the film forming section to form a film on a substrate, and when the flow rate of the carrier gas is set to Q (L / min) and the temperature of the carrier gas is set to T (°C), the flow rate of the carrier gas and the temperature of the carrier gas are controlled in a manner of 7 < T + Q < 67. Thus, a film forming method with excellent film forming speed can be provided.

Description

Technical Field

[0001] The present invention relates to a film forming method for forming a film on a substrate using a mist-like raw material. Background Art

[0002] In the past, a high vacuum film-forming device capable of realizing non-equilibrium state such as pulsed laser deposition (PLD), molecular beam epitaxy (MBE), and sputtering has been developed, making it possible to produce oxide semiconductors that could not be produced by the previous melting method. In addition, a mist chemical vapor deposition method (Mist Chemical Vapor Deposition: Mist CVD. Hereinafter also referred to as "mist CVD method") has been developed that uses atomized mist raw materials to grow crystals on a substrate, thereby making it possible to produce gallium oxide (α-Ga2O3) with a corundum structure. As a semiconductor with a large band gap, α-Ga2O3 can be expected to be used in the next generation of switching elements that can achieve high withstand voltage, low loss and high heat resistance.

[0003] Regarding the atomization CVD method, Patent Document 1 describes a tube furnace type atomization CVD device. Patent Document 2 describes a microchannel type atomization CVD device. Patent Document 3 describes a line source type atomization CVD device. Patent Document 4 describes a tube furnace atomization CVD device, which differs from the atomization CVD device described in Patent Document 1 in that a carrier gas is introduced into the mist generator. Patent Document 5 describes an atomization CVD device in which a substrate is provided above the mist generator and the base is a rotating table mounted on a heating plate.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 1-257337

[0007] Patent Document 2: Japanese Patent Application Publication No. 2005-307238

[0008] Patent Document 3: Japanese Patent Application Publication No. 2012-46772

[0009] Patent Document 4: Japanese Patent No. 5397794

[0010] Patent Document 5: Japanese Patent Application Publication No. 2014-63973 Summary of the invention

[0011] Technical Problems to be Solved by the Invention

[0012] Unlike other CVD methods, the atomization CVD method does not require high temperatures and can produce metastable crystal structures such as the corundum structure of α-gallium oxide.

[0013] However, the influence of carrier gas temperature has not been considered so far. That is, it is known that if the carrier gas source is arranged outdoors or in a room without air conditioning, the temperature of the carrier gas will change, which will have a great influence on the film formation rate.

[0014] In this regard, the inventors of the present invention have discovered the following new problem, namely, the generated mist will condense and form dew in the supply pipe before being transported to the substrate (the life of the mist is reduced), and the condensed mist cannot be delivered to the film forming part, so the film forming speed is reduced, and it was found that when the carrier gas flow rate is small, the impact of this problem is more significant.

[0015] Furthermore, the inventors of the present invention have discovered the following new problem, namely, if a carrier gas is introduced into the supply pipe, the water vapor partial pressure in the pipe decreases, resulting in the dissipation (evaporation) of the mist, a decrease in the amount of mist involved in film formation, and a decrease in the film formation speed. It has also been found that when the carrier gas flow rate is larger, the impact of this problem is more pronounced.

[0016] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a film forming method having an excellent film forming speed.

[0017] Technical means to solve technical problems

[0018] The present invention is completed to achieve the above-mentioned purpose. The present invention provides a film-forming method, which is a film-forming method for performing heat treatment on mist in a film-forming section to perform film formation, and the method comprises: a process of atomizing a raw material solution in an atomizing section to generate mist; a process of transporting the mist from the atomizing section to the film-forming section via a transport section connecting the atomizing section and the film-forming section by a carrier gas; and a process of performing heat treatment on the mist in the film-forming section to perform film formation on a substrate, wherein when the flow rate of the carrier gas is set to Q (L / min) and the temperature of the carrier gas is set to T (°C), the flow rate of the carrier gas and the temperature of the carrier gas are controlled in a manner of 7<T+Q<67.

[0019] According to this film forming method, the film forming speed can be greatly improved by a simple method.

[0020] In this case, the film forming method may be such that T+Q satisfies 17<T+Q<57.

[0021] This makes it possible to more reliably and significantly improve the film formation speed.

[0022] In this case, the film forming method may be such that T+Q satisfies 27<T+Q<47.

[0023] This makes it possible to increase the film formation rate more stably.

[0024] Effects of the Invention

[0025] As described above, according to the film forming method of the present invention, the film forming speed can be greatly improved by a simple method. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 1 is a schematic structural diagram showing an example of a film forming apparatus used in the film forming method of the present invention.

[0027] Figure 2 This is a diagram for explaining an example of an atomizing section in a film forming apparatus.

[0028] Figure 3 It is a graph showing the relationship between the carrier gas temperature T and the film formation rate.

[0029] Figure 4 It is a graph showing the relationship between the sum (T+Q) of the carrier gas temperature T and the carrier gas flow rate Q and the film formation rate. DETAILED DESCRIPTION

[0030] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0031] As described above, in the atomization CVD method, a film forming method which can greatly improve the film forming speed is sought.

[0032] The inventors of the present invention have conducted careful research on the above-mentioned problems, and as a result, they have found that the dissipation of the mist in the conveying section can be simply suppressed by the following film-forming method, thereby extending the life of the mist in the conveying section and increasing the film-forming speed, thereby completing the present invention. The film-forming method is a method of forming a film by heat-treating the mist in the film-forming section, which includes: a process of atomizing the raw material solution in the atomization section to generate mist; a process of transporting the mist from the atomization section to the film-forming section via a conveying section connecting the atomization section and the film-forming section by a carrier gas; and a process of heat-treating the mist in the film-forming section to form a film on a substrate, and when the flow rate of the carrier gas is set to Q (L / min) and the temperature of the carrier gas is set to T (°C), the flow rate of the carrier gas and the temperature of the carrier gas are controlled in a manner of 7<T+Q<67.

[0033] Hereinafter, description will be given with reference to the drawings.

[0034] Here, the mist referred to in the present invention is a general term for fine particles of liquid dispersed in gas, and includes substances called mist, droplets, and the like.

[0035] Figure 11 shows an example of a film forming apparatus 101 that can be used in the film forming method of the present invention. The film forming apparatus 101 includes: an atomizing section 120 that atomizes a raw material solution to generate mist, a carrier gas supply section 130 that supplies a carrier gas for transporting the mist, a film forming section 140 that performs a heat treatment on the mist to form a film on a substrate, and a transport section 109 that connects the atomizing section 120 and the film forming section 140 and transports the mist through the carrier gas. In addition, the film forming apparatus 101 can be provided with a control section (not shown) that controls the entire or a part of the film forming apparatus 101 to control its operation.

[0036] (Atomization part)

[0037] In the atomizing unit 120, the raw material solution 104a is adjusted so that the raw material solution 104a is atomized to generate mist. There is no particular limitation on the atomizing means as long as the raw material solution 104a can be atomized, and it can be a known atomizing means, but it is preferable to use an atomizing means using ultrasonic vibration. This is because atomization can be performed more stably.

[0038] An example of such atomizing unit 120 is shown in Figure 2 For example, it may include a mist generating source 104 containing a raw material solution 104a, a container 105 containing a medium that can transmit ultrasonic vibrations, such as water 105a, and an ultrasonic vibrator 106 installed on the bottom surface of the container 105. In detail, the mist generating source 104 composed of a container containing the raw material solution 104a is stored in the container 105 containing water 105a using a support body (not shown). An ultrasonic vibrator 106 is installed at the bottom of the container 105, and the ultrasonic vibrator 106 is connected to the vibrator 116. And, it is constructed in the following manner: if the vibrator 116 is operated, the ultrasonic vibrator 106 vibrates, and the ultrasonic wave is transmitted to the mist generating source 104 via the water 105a, and the raw material solution 104a is atomized.

[0039] (Film Forming Department)

[0040] Refer again Figure 1 In the film forming unit 140, the mist is heated to cause a thermal reaction, and a film is formed on a part of the surface or the entire surface of the substrate 110. The film forming unit 140 includes, for example, a film forming chamber 107, in which the substrate 110 is disposed, and may also include a heating plate 108 for heating the substrate 110. The heating plate 108 may be as follows: Figure 1 Although shown as being disposed outside the film forming chamber 107, it may also be disposed inside the film forming chamber 107. In addition, the film forming chamber 107 is provided with an exhaust port 112 for exhausting gas at a position that does not affect the supply of mist to the substrate 110.

[0041] In the present invention, the substrate 110 may be disposed on the upper surface of the film forming chamber 107 so as to face downward, or may be disposed on the bottom surface of the film forming chamber 107 so as to face upward.

[0042] As for the thermal reaction, as long as the mist reacts by heating, the reaction conditions are not particularly limited. It can be appropriately set according to the raw materials or the film-forming material. For example, the heating temperature is in the range of 120 to 600° C., preferably in the range of 200 to 600° C., and more preferably in the range of 300 to 550° C.

[0043] The thermal reaction can be carried out in any of the following atmospheres: vacuum, oxygen-free atmosphere, reducing gas atmosphere, air atmosphere, and oxygen atmosphere, and can be appropriately set according to the film-forming material. In addition, the reaction pressure can also be carried out under any of the following conditions: atmospheric pressure, pressurized, or reduced pressure. However, if the film is formed under atmospheric pressure, the device structure can be simplified, so it is preferred.

[0044] (Conveying Department)

[0045] The transport unit 109 connects the atomizing unit 120 and the film forming unit 140. The mist is transported from the mist generating source 104 of the atomizing unit 120 to the film forming chamber 107 of the film forming unit 140 via the transport unit 109 through the carrier gas. The transport unit 109 can be formed as a supply pipe 109a, for example. For example, a quartz pipe or a resin pipe can be used as the supply pipe 109a.

[0046] (Raw material solution)

[0047] The raw material solution 104a is not particularly limited as long as it contains a material that can be atomized, and can be an inorganic material or an organic material. Metals or metal oxides are preferably used, and substances containing one or more metals selected from gallium, iron, indium, aluminum, vanadium, titanium, chromium, rhodium, nickel and cobalt can be used.

[0048] The raw material solution 104a is not particularly limited as long as it is a substance that can atomize the above-mentioned metal, but it is suitable to use a substance that dissolves or disperses the above-mentioned metal in the form of a complex or a salt in an organic solvent or water as the raw material solution 104a. As the form of the complex, for example, acetylacetone complex, carbonyl complex, ammonia complex, hydrogenation complex, etc. can be listed. As the form of the salt, for example, chloride metal salt, bromide metal salt, iodide metal salt, etc. can be listed. In addition, a substance obtained by dissolving the above-mentioned metal in hydrobromic acid, hydrochloric acid, hydroiodic acid, etc. can also be used as an aqueous solution of the salt.

[0049] In addition, additives such as hydrohalic acid or oxidizing agent may be mixed in the raw material solution 104a. As the hydrohalic acid, for example, hydrobromic acid, hydrochloric acid, hydroiodic acid, etc. may be listed, among which hydrobromic acid or hydroiodic acid is preferred. As the oxidizing agent, for example, peroxides such as hydrogen peroxide (H2O2), sodium peroxide (Na2O2), barium peroxide (BaO2), benzoyl peroxide (C6H5CO)2O2, hypochlorous acid (HClO), perchloric acid, nitric acid, ozone water, peracetic acid or nitrobenzene, etc. may be listed.

[0050] Furthermore, the raw material solution may contain a dopant. The dopant is not particularly limited. For example, n-type dopants such as tin, germanium, silicon, titanium, zirconium, vanadium, or niobium, or p-type dopants such as copper, silver, tin, iridium, or rhodium may be listed. The concentration of the dopant may be, for example, about 1×10 16 / cm 3 ~1×10 22 / cm 3 , or it can be set to about 1×10 17 / cm 3 The following low concentrations can also be set to 1×10 20 / cm 3 Above high concentration.

[0051] (Matrix)

[0052] The substrate 110 is not particularly limited as long as it can form a film and support the film. The material of the substrate 110 is also not particularly limited, and a known substrate can be used, which can be an organic compound or an inorganic compound. For example, polysulfone, polyethersulfone, polyphenylene sulfide, polyetheretherketone, polyimide, polyetherimide, fluororesin, iron or aluminum, stainless steel, metals such as gold, silicon, sapphire, quartz, glass, gallium oxide, etc. can be listed, but it is not limited to this. As for the shape of the substrate, any shape is acceptable, and any shape is effective. For example, a plate-like shape such as a flat plate or a circular plate, a fiber shape, a rod shape, a cylindrical shape, a prism shape, a tube shape, a spiral shape, a sphere or a ring shape can be listed, but in the present invention, a plate-like substrate is preferred. The thickness of the plate-like substrate is not particularly limited, but is preferably 10 to 2000 μm, and more preferably 50 to 800 μm. When the substrate is in the form of a plate, its area is preferably 100 mm 2 More preferably, the diameter is 2 inches (50 mm) or more.

[0053] (Carrier gas supply unit)

[0054] The carrier gas supply unit 130 includes a carrier gas source 102a for supplying a carrier gas, and may also include a flow control valve 103a for adjusting the flow rate of the carrier gas (hereinafter referred to as "main carrier gas") output from the carrier gas source 102a. In addition, a dilution carrier gas source 102b for supplying a dilution carrier gas and a flow control valve 103b for adjusting the flow rate of the dilution carrier gas output from the dilution carrier gas source 102b may also be provided as needed.

[0055] The type of carrier gas is not particularly limited and can be appropriately selected according to the film-forming material. For example, inert gases such as oxygen, ozone, nitrogen and argon, or reducing gases such as hydrogen or forming gas, etc. can be listed. In addition, the type of carrier gas can be one or more than two. For example, a diluted gas obtained by diluting the same gas as the first carrier gas with a gas other than the first carrier gas (for example, diluting it by 10 times) can be further used as the second carrier gas, or air can be used.

[0056] In addition, the carrier gas supply position may be not only one position but also two or more positions.

[0057] In the present invention, the carrier gas flow rate Q refers to the total flow rate of the carrier gas. In the above example, the total flow rate of the main carrier gas output from the carrier gas source 102a and the flow rate of the dilution carrier gas output from the dilution carrier gas source 102b is set as the carrier gas flow rate Q.

[0058] The flow rate Q of the carrier gas is not particularly limited, but when forming a film on a 30 mm square substrate, for example, it is preferably set to 0.01 to 60 L / min, and more preferably 1 to 30 L / min.

[0059] (Carrier gas temperature control unit)

[0060] The film forming device 101 has a carrier gas temperature control unit 150 that can adjust the temperature T of the carrier gas. The method for controlling the temperature T of the carrier gas is not particularly limited. For example, there can be cited a method of winding a pipe of water with adjusted temperature around the carrier gas pipe part. In addition, heating can be performed by installing a heating jacket, heating the pipe part with infrared rays, etc. In addition, when controlled to a low temperature, the carrier gas pipe can be cooled by arranging it in a freezer, or the pipe part can be directly cooled using a refrigerant such as liquid nitrogen or Freon, or indirectly cooled via a pipe, etc. When the carrier gas sources 102a, 102b are containers, the temperature of the container itself can be controlled by the method as described above, or the carrier gas temperature T can be controlled by controlling the temperature of the room where the container is set.

[0061] like Figure 1As shown, it is preferred to control the temperature T of the carrier gas in the carrier gas supply section 130 so that it can be easily supplied to the conveying section 109. However, as long as the temperature T of the carrier gas can be quickly controlled, the temperature of the carrier gas can also be controlled at the connection between the carrier gas supply section 130 and the conveying section 109 and / or the connection between the carrier gas supply section 130 and the atomizing section 120.

[0062] The present invention is characterized in that the temperature T of the carrier gas and the flow rate Q of the carrier gas are used as parameters, and T and Q are controlled respectively so that T+Q is within a predetermined range to form a film. T+Q will be described in detail later.

[0063] (Film Forming Method)

[0064] Next, refer to the following Figure 1 An example of the film forming method of the present invention will be described.

[0065] First, the raw material solution 104 a is stored in the mist generating source 104 of the atomizing unit 120 , and the substrate 110 is placed directly on the heating plate 108 or on the heating plate 108 via the wall of the film forming chamber 107 , and the heating plate 108 is operated.

[0066] In addition, in the carrier gas temperature control unit 150 , the carrier gas is heated or cooled, thereby controlling the temperature T of the carrier gas.

[0067] Next, open the flow regulating valves 103a and 103b to supply the carrier gas from the carrier gas sources 102a and 102b into the film forming chamber 107, fully replace the atmosphere in the film forming chamber 107 with the carrier gas, and simultaneously adjust the flow rates of the main carrier gas and the dilution carrier gas respectively, thereby controlling the flow rate Q of the carrier gas.

[0068] In the mist generation process, the ultrasonic vibrator 106 is vibrated, and the vibration is transmitted to the raw material solution 104a through the water 105a, thereby atomizing the raw material solution 104a to generate mist. Next, in the mist transport process by the carrier gas, the mist is transported from the atomizing unit 120 to the film forming unit 140 via the transport unit 109 by the carrier gas, and then introduced into the film forming chamber 107. In the film forming process, the mist introduced into the film forming chamber 107 is heat-treated in the film forming chamber 107 due to the heating of the heating plate 108, and then a thermal reaction occurs, and a film is formed on the substrate 110.

[0069] The inventors of the present invention have examined the film formation rate with attention paid to the carrier gas flow rate Q and the carrier gas temperature T, and the results are described here.

[0070] Using the above film formation method, the relationship between the carrier gas flow rate Q (L / min), carrier gas temperature T (°C), and film formation speed (μm / hour) was investigated. Figure 3The results are shown in . The vertical axis represents the film formation rate, the horizontal axis represents the carrier gas temperature T, and each carrier gas flow rate Q is plotted.

[0071] Focusing on the carrier gas flow rate Q = 5.5 L / min, it can be seen that the film formation rate reaches a maximum at around the carrier gas temperature T = 40°C, and rapidly decreases in the range of the carrier gas temperature T being below about 0°C and above about 60°C. Similarly, when the carrier gas flow rate Q = 22 L / min, it reaches a maximum at around the carrier gas temperature T = 20°C, and rapidly decreases in the range of the carrier gas temperature T being below about -15°C and above about 45°C. When the carrier gas flow rate Q = 44 L / min, it reaches a maximum at around the carrier gas temperature T = -5°C, and rapidly decreases in the range of the carrier gas temperature T being below about -35°C and above about 25°C.

[0072] It can be seen from this that the optimal temperature range of the carrier gas varies depending on the carrier gas flow rate Q.

[0073] However, when the carrier gas temperature is set to T (°C) and the carrier gas flow rate is set to Q (L / min), if the relationship between T+Q and the film forming rate is sorted out, it is surprisingly found that regardless of the carrier gas flow rate Q and the carrier gas temperature T, the film forming rate reaches the maximum when T+Q is about 40, and the film forming rate drops rapidly when T+Q is below 7 and above 67 ( Figure 4 In other words, when the carrier gas temperature is set to T (°C) and the carrier gas flow rate is set to Q (L / min), as long as the relationship 7<T+Q<67 is satisfied, a high film formation rate can be stably achieved regardless of the values ​​of T and Q.

[0074] As described above, according to the present invention, when the temperature of the carrier gas is set to T (°C) and the flow rate of the carrier gas is set to Q (L / min), by controlling the temperature T of the carrier gas and the flow rate Q of the carrier gas in a manner of 7 < T + Q < 67, the condensation and evaporation of the mist at the conveying part 109 can be suppressed, and the film forming speed can be improved. The range of T + Q is preferably 17 < T + Q < 57, which can more reliably improve the film forming speed. More preferably, it is 27 < T + Q < 47, which can further stably increase the film forming speed.

[0075] When 7≥T+Q, that is, 7-Q≥T, the water vapor in the pipe of the conveying unit 109 is supersaturated, and the supersaturated water vapor condenses with the mist as the nucleus. It is believed that the mist becomes thicker and the settling speed increases, and a large amount of mist settles and condenses in the pipe, and the amount of mist delivered to the film forming unit decreases, resulting in a decrease in the film forming speed.

[0076] In addition, when T+Q≥67, that is, T≥67-Q, the saturated water vapor pressure in the pipe of the conveying unit 109 increases. It is believed that in order to use water vapor to evaporate the saturated mist in the pipe, the amount of mist sent to the film forming unit will also decrease, resulting in a decrease in the film forming speed. Although the total amount of water sent to the film forming unit is the same, the amount of mist that can participate in film formation is reduced.

[0077] The temperature T of the carrier gas is the temperature of the carrier gas in the transport section 109. In order to suppress the reduction in the amount of mist in the transport section 109, it is desirable that the relationship of 7<T+Q<67 is satisfied in the entire area of ​​the transport section 109.

[0078] Regarding the carrier gas temperature T, it is preferred to directly measure the carrier gas temperature at the connection between the carrier gas supply section 130 and the transport section 109 and / or the connection between the carrier gas supply section 130 and the atomization section 120, but under a stable state, the temperature of the outer wall of the pipeline at this location can also be used instead.

[0079] Sometimes, the temperature change of the carrier gas can be ignored depending on the length of the conveying section 109 or the environment in which the conveying section 109 is installed, and the temperature of the conveying section 109 does not necessarily need to be adjusted. However, if a temperature adjustment device is provided in the conveying section 109 to control the temperature, T+Q can be controlled more stably, which is preferred. In addition, it is further preferred to measure the temperature at the connection portion between the conveying section 109 and the film forming section 140 to control the carrier gas temperature T. In this way, T+Q can be controlled more stably.

[0080] In addition, as long as the relationship 7<T+Q<67 is satisfied, the carrier gas temperature T is not necessarily required to be constant throughout the entire area of ​​the transport section. For example, 7<T+Q<67 can be transformed into 7-Q<T<67-Q, and it is allowed to vary within a range corresponding to the set carrier gas flow rate Q.

[0081] Example

[0082] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the Examples.

[0083] (Example 1)

[0084] According to the above-mentioned film forming method, a film of gallium oxide (α-Ga2O3) having a corundum structure is formed.

[0085] Specifically, first, a 0.1 mol / L gallium bromide aqueous solution was prepared, and further a 48% hydrobromic acid solution was contained so as to have a volume ratio of 10%, and this was used as the raw material solution 104a.

[0086] The raw material solution 104a obtained in the above manner is stored in the mist generating source 104. The temperature of the solution at this time is 25°C. Next, a 4-inch (100 mm in diameter) c-plane sapphire substrate is set as the base 110 in the film forming chamber 107 adjacent to the heating plate 108, and the heating plate 108 is operated to raise the temperature to 500°C.

[0087] Next, the flow regulating valves 103a and 103b are opened to supply oxygen as carrier gas from the carrier gas sources 102a and 102b into the film forming chamber 107, and the atmosphere of the film forming chamber 107 is fully replaced with the carrier gas, and at the same time, the flow rate of the main carrier gas is adjusted to 5 L / min and the flow rate of the dilution carrier gas is adjusted to 0.5 L / min, respectively. That is, the carrier gas flow rate Q is set to 5.5 L / min.

[0088] As the carrier gas temperature control unit 150 , a pipe of temperature-controlled water is wound around the carrier gas supply pipe, thereby adjusting the carrier gas temperature T.

[0089] In Example 1, the temperature T of the carrier gas was set to 45° C. That is, T+Q=50.5.

[0090] Next, the ultrasonic vibrator 106 is vibrated at 2.4 MHz, and the vibration is transmitted to the raw material solution 104a through the water 105a, thereby atomizing the raw material solution 104a to generate mist. The mist is introduced into the film forming chamber 107 through the supply pipe 109a by the carrier gas. Next, the mist is thermally reacted in the film forming chamber 107 under the conditions of atmospheric pressure and 500°C, and a thin film of gallium oxide (α-Ga2O3) having a corundum structure is formed on the substrate 110. The film forming time is 30 minutes.

[0091] The growth rate was evaluated in the following manner. First, for the thin film on the substrate 110, the film thickness was measured at 17 points within the surface of the substrate 110 as the measurement locations using a step profiler, and the average film thickness was calculated from the values ​​of the individual film thicknesses. The value obtained by dividing the obtained average film thickness by the film formation time was taken as the film formation rate.

[0092] (Comparative Example 1)

[0093] Film formation and evaluation were performed under the same conditions as in Example 1 except that the carrier gas temperature T was set to 74° C., that is, T+Q=79.5.

[0094] (Example 2)

[0095] Film formation and evaluation were performed under the same conditions as in Implementation 1, except that the flow rates of the main carrier gas and the dilution carrier gas were adjusted to 20 L / min and 2 L / min, respectively, so that the carrier gas flow rate Q = 22 L / min, and the temperature T of the carrier gas was set to 10°C, i.e., T+Q = 32.

[0096] (Comparative Example 2)

[0097] Film formation and evaluation were performed under the same conditions as in Example 2 except that the temperature T of the carrier gas was set to 55° C., that is, T+Q=77.

[0098] (Example 3)

[0099] Film formation and evaluation were performed under the same conditions as in Implementation 1, except that the flow rates of the main carrier gas and the dilution carrier gas were adjusted to 40 L / min and 4 L / min, respectively, so that the carrier gas flow rate Q = 44 L / min, and the temperature T of the carrier gas was set to 20°C, i.e., T+Q = 64.

[0100] (Comparative Example 3)

[0101] Film formation and evaluation were performed under the same conditions as in Example 3 except that the temperature T of the carrier gas was set to 35° C., that is, T+Q=79.

[0102] Table 1 shows the conditions of Examples 1 to 3 and Comparative Examples 1 to 3 and the results of evaluation of the film formation rate.

[0103] [Table 1]

[0104]

[0105] It is obvious from the comparison between Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, and Example 3 and Comparative Example 3, which have the same carrier gas flow rate, that the film formation speed is greatly different between the case of 7<T+Q<67 and other cases. In addition, as long as 7<T+Q<67 is satisfied, a high film formation speed can be achieved regardless of the values ​​of T and Q.

[0106] As a result, the film forming speed can be greatly improved by a simple method.

[0107] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any technical solution having substantially the same structure and achieving the same effect as the technical concept described in the claims of the present invention is included in the technical scope of the present invention.

Claims

1. A film forming method, wherein the film is formed by heat treating mist in a film forming part, characterized in that: include: A step of atomizing the raw material solution to generate mist in an atomizing section; The step of transporting the mist from the atomizing section to the film forming section by a carrier gas via a transporting section connecting the atomizing section and the film forming section; as well as The mist is subjected to heat treatment in the film forming unit to form a film on a substrate. In the film forming method, when the flow rate of the carrier gas is set to QL / min and the temperature of the carrier gas is set to T°C, the flow rate of the carrier gas and the temperature of the carrier gas are controlled in a manner of 7<T+Q<67, water is used as the solvent of the raw material solution, the pressure of the film forming part is set to atmospheric pressure, and the flow rate Q of the carrier gas is set to 0.01~60L / min.

2. The film forming method according to claim 1, characterized in that: The T+Q is set to be 17<T+Q<57.

3. The film forming method according to claim 1 or 2, characterized in that: The T+Q is set to be 27<T+Q<47.

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